JP6220663B2 - Expandable styrene resin particles imparted with flame retardancy and process for producing the same - Google Patents

Description

  The present invention relates to an expandable polystyrene resin particle and a polystyrene resin foam molded article having flame retardancy and a low residual styrene content.

  Polystyrene resin foam is widely used for construction and civil engineering applications, but it is often required to have flame retardant performance when used for housing-related materials, etc., and expandable polystyrene resin foam containing flame retardant etc. Is often used.

  In recent years, environmental issues have been emphasized, and many studies have been made to reduce volatile organic substances contained in plastic products. In particular, various regulations have begun to be set for resin molded products used for housing-related materials due to the sick house problem, etc., and it is very important to reduce the volatile organic substances present in the raw material resin constituting the member. It is getting important.

  In addition, phenylacetylene produced as a by-product in the process of producing a styrene monomer acts as a polymerization inhibitor in the polymerization of styrene, and if the amount of phenylacetylene is large, the amount of residual styrene in the final product increases. In a member that requires light volatile organic matter, a styrene monomer that is a low concentration of phenylacetylene is used as a raw material in order to reduce the amount of residual styrene.

  As for expandable styrene resin particles, studies are underway to reduce the amount of residual styrene in resin particles, mainly in building materials, food trays, containers and the like. For example, Patent Document 1 and Patent Document 2 describe expandable styrene resin particles that change the plasticizer to a non-volatile one and reduce the amount of residual styrene contained in the expandable styrene resin particles. The purpose is achieved by increasing the temperature or increasing the polymerization time. However, in a polymerization system using a hydrocarbon-based blowing agent or a polymerization system using a halogen-based flame retardant for imparting flame retardancy, for example, the primary radical of the initiator is a hydrocarbon-based blowing agent or a halogen-based flame retardant. In contrast, since the hydrogen abstraction reaction is performed, the amount of residual styrene is difficult to decrease even when polymerization is performed at a high temperature for a long time, which is a general method.

  Patent Document 3 describes a method for reducing the amount of residual styrene to 300 ppm or less. However, after adding butane as a foaming agent, the reaction is carried out at 120 ° C. for 6 hours. doing.

  Patent Document 4 uses a low-temperature polymerization initiator having a 10-hour half-life temperature of 50 ° C. to 80 ° C. and n-butyl-4,4-bis (t-butylperoxy) valerate to prevent water leakage. A method for producing excellent expandable styrenic resin particles is disclosed. However, there is no description regarding the amount of residual styrene, and particularly in a system containing a flame retardant, there is a problem that the amount of residual styrene is not sufficiently lowered by the method disclosed in the patent literature.

  Patent Documents 5 and 6 have a ketal structure such as 1,1-bis (t-amylperoxy) -3,3,5-trimethylcyclohexane, and a 10-hour half-life temperature of 100 ° C. or higher and 110 ° C. or lower. A production method is disclosed in which the amount of residual styrene in the expandable styrenic resin particles is significantly reduced by using together the initiator. However, when a styrene monomer having a phenylacetylene content of 50 ppm or more is used, this method has a problem that the residual styrene content is not easily lowered.

  Patent Document 7 discloses that a brominated butadiene / vinyl aromatic copolymer is used as a flame retardant, but it is extrusion foaming by blending with a styrene resin, and there is no description of residual styrene.

JP 2002-356575 A Japanese Patent Laid-Open No. 10-17698 JP-A-11-106548 Japanese Patent No. 3597109 Japanese Patent No. 4494074 Japanese Patent No. 5109227 JP2013-116958A

  An object of the present invention is to use a styrene monomer having a phenylacetylene content of 80 ppm or more and to make the residual monomer content in the expandable styrene resin particles containing a halogen flame retardant 300 ppm or less. It is providing the manufacturing method of the expandable styrene-type resin particle which has performance.

  As a result of intensive investigations, the present inventors have adopted expandable polystyrene resin particles imparted with flame retardancy without reducing productivity by adopting a specific flame retardant and further a specific polymerization initiator. It has been found that the amount of the remaining styrene monomer can be efficiently reduced, and the present invention has been completed. That is, the present invention is as follows.

  [1] Containing 0.5 parts by weight or more and 5.0 parts by weight or less of a brominated polymer with respect to 100 parts by weight of a styrene monomer having an amount of phenylacetylene of 80 ppm or more, and represented by the general formula (1) A styrene monomer is polymerized using 0.05 to 0.6 parts by weight of a compound as a polymerization initiator, and propane, isobutane, normal butane, isopentane as a foaming agent during or after the polymerization , Foamable polystyrene resin particles obtained by impregnating at least one selected from the group consisting of normal pentane and neopentane, wherein the residual styrene monomer content is 300 ppm or less Polystyrene resin particles.

(In the formula, R ₁ represents an alkyl group, and R ₂ represents a branched or straight chain alkyl group.)
[2] The expandable polystyrene resin particles according to [1], wherein the brominated polymer is a brominated butadiene / vinyl aromatic copolymer.

[3] The expandable polystyrene according to [1] or [2], wherein the R ₁ structure of the general formula (1) is a methyl group or an ethyl group, and the R ₂ structure is an ethylhexyl group or an isopropyl group Resin particles.

  [4] The expandable polystyrene resin according to any one of [1] to [3], wherein the compound represented by the general formula (1) has a 10-hour half-life temperature of 96 ° C to 110 ° C. particle.

  [5] The expandable polystyrene resin particles according to any one of [1] to [4], wherein the foaming agent is impregnated at a temperature of 110 ° C. to 120 ° C.

  [6] A polystyrene resin foam molded article obtained by foaming the expandable polystyrene resin particles according to any one of [1] to [5].

  [7] The method for producing expandable polystyrene resin particles according to any one of [1] to [5].

  According to the present invention, expandable polystyrene resin particles having flame retardancy can be obtained without reducing productivity, and the amount of styrene monomer remaining in the expandable polystyrene resin particles Can be efficiently reduced.

  Hereinafter, embodiments of the present invention will be described in more detail.

  The expandable polystyrene polymer particles in the present invention are 0.5 parts by weight or more and 5.0 parts by weight or less of a brominated polymer with respect to 100 parts by weight of a styrene monomer having a phenylacetylene content of 80 ppm or more. A styrenic monomer is polymerized using 0.05 to 0.6 parts by weight of a compound represented by the general formula (1) as a polymerization initiator, and during or after the polymerization, a foaming agent Expandable polystyrene resin particles obtained by impregnating at least one selected from the group consisting of propane, isobutane, normal butane, isopentane, normal pentane and neopentane, and the residual styrene monomer content is 300 ppm or less It is an expandable polystyrene resin particle characterized by being.

(In the formula, R ₁ represents an alkyl group, and R ₂ represents a branched or straight chain alkyl group.)
Examples of the styrene monomer used in the present invention include styrene and styrene derivatives such as α-methyl styrene, paramethyl styrene, t-butyl styrene, chlorostyrene, and components capable of copolymerization with styrene. For example, esters of acrylic acid and methacrylic acid such as methyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, cetyl methacrylate, or various monomers such as acrylonitrile, dimethyl fumarate, ethyl fumarate, divinylbenzene, alkylene glycol dimethacrylate Bifunctional monomers such as are also included. One or more of these copolymerizable components may be used for copolymerization.

  Phenylacetylene produced as a by-product in the production process of styrene monomer acts as a polymerization inhibitor. When the amount of phenylacetylene is 80 ppm or more, the amount of residual styrene in the foamable styrene resin particles of the final product increases. . On the other hand, when the amount of phenylacetylene is less than 80 ppm, the amount of residual styrene in the foamable polystyrene resin particles of the final product decreases, but a step of removing phenylacetylene is required, and the cost of the styrene monomer itself increases. The upper limit of the amount of phenylacetylene is 400 ppm with styrene called general purpose.

  Examples of the dispersant used in the present invention include dispersants generally used for suspension polymerization, such as poorly water-soluble inorganic salts such as calcium phosphate, hydroxyapatite, and magnesium pyrophosphate. When these poorly water-soluble inorganic salts are used, the use of an anionic surfactant such as α-olefin sodium sulfonate or dodecylbenzene sodium sulfonate is effective because the dispersion stability increases. Further, the hardly soluble inorganic salt may be added one or more times during the polymerization in order to adjust the particle diameter of the resulting expandable styrene resin particles.

The polymerization initiator used in the present invention is a compound represented by the general formula (1), R ₁ is an alkyl group, R ₂ has a branched or straight chain alkyl group structure, and specifically, T-butylperoxy-2-ethylhexyl monocarbonate, t-amylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxyisopropyl monocarbonate, and the like.

(In the formula, R ₁ represents an alkyl group, and R ₂ represents a branched or straight chain alkyl group.)
In particular, among the compounds of the general formula (1), the R ₁ structure is a methyl group or an ethyl group, the R ₂ structure is an ethylhexyl group or an isopropyl group, and the 10-hour half-life temperature is 96 ° C. or higher and 110 ° C. or lower. A certain compound is preferable because it can reduce the amount of residual styrene in the expanded styrene resin particles as the final product. Examples thereof include t-butyl peroxy-2-ethylhexyl monocarbonate (10 hour half-life temperature 99 ° C.), t-amyl peroxy-2-ethylhexyl monocarbonate (98.5 ° C.), and the like.

  The amount of the compound represented by the general formula (1) varies depending on the molecular weight of the foamable styrene resin particles to be obtained, but is 0.05 parts by weight or more and 0.6 parts by weight with respect to 100 parts by weight of the styrene monomer. Or less, preferably 0.1 parts by weight or more and 0.5 parts by weight or less, more preferably 0.2 parts by weight or more and 0.4 parts by weight or less. When the amount of the compound represented by the general formula (1) is within the above range, a resin having an appropriate molecular weight can be obtained and the amount of residual styrene can be reduced. Even if it is less than 0.05 parts by weight, the effect of reducing the amount of residual styrene is exhibited, but a long reaction time may be required. Moreover, although an upper limit is 0.6 weight part, the effect of reducing the amount of residual styrene-type monomers does not change, but there exists a tendency for the molecular weight of resin to fall and cost becomes high.

  In the present invention, when a compound having a 10-hour half-life temperature of 96 ° C. or higher and 110 ° C. or lower is used in the general formula (1), the amount of residual styrene can be further reduced while suppressing a decrease in molecular weight. Is possible. For this compound, it is important that the 10-hour half-life temperature is 96 ° C. or higher and 110 ° C. or lower. If it is within this range, the amount of cleavage during polymerization is suppressed as much as possible, and the heat treatment or the blowing agent impregnation step is efficiently performed. The amount of residual styrene can be reduced. A 10-hour half-life temperature of less than 95 ° C. is not preferable because the amount of cleavage during polymerization increases and the molecular weight of the resin decreases. As a solution to this problem, it is possible to lower the polymerization temperature. However, in this case, the polymerization time is extended, which is not preferable for industrial production. Conversely, when the 10-hour half-life temperature exceeds 110 ° C., the amount of initiator that cleaves during heat treatment or foaming agent impregnation is insufficient, and the amount of residual styrene cannot be reduced sufficiently.

  In the production of expandable styrenic resin particles, generally, an initiator mainly for forming a resin and an initiator mainly for reducing the amount of residual styrene are generally used in combination. The selection of these initiators is appropriately determined in consideration of the polymerization temperature, the polymerization time, and the required molecular weight of the resin. Therefore, also in the present invention, the polymerization temperature, the polymerization time, the molecular weight of the resin, etc. can be selected by using one or more commonly used other polymerization initiators in combination with the compound represented by the general formula (1). Since it is possible to obtain a good product in which the amount of residual styrene is reduced while further widening the width, it is a very preferable embodiment to use in combination. Examples of other commonly used polymerization initiators include organic oxides such as benzoyl peroxide, t-butyl peroxybenzoate, isopropyl t-butyl peroxycarbonate, butyl perbenzoate, and azobisisobutyrate. Examples include azo compounds such as ronitrile.

  The flame retardant used in the present invention is a brominated polymer. Brominated styrene, brominated butadiene-vinyl aromatic copolymer, brominated novolak resin allyl ether, brominated poly (1,3-cycloalkadiene) and brominated poly (4-vinylphenol allyl ether).

  Of these, a brominated butadiene / vinyl aromatic copolymer is preferred because it is easy to obtain flame retardancy. Among brominated butadiene / vinyl aromatic copolymers, brominated butadiene / styrene copolymers are more preferable because high flame retardancy is easily obtained. The styrene-butadiene copolymer before bromination is diblock copolymer (for example, styrene / butadiene block copolymer), triblock copolymer (for example, styrene / butadiene / styrene block copolymer), tetrablock copolymer The polymer may be a polymer (for example, styrene / butadiene / styrene / butadiene block copolymer) or a multi-block copolymer (for example, styrene / butadiene / styrene / butadiene / styrene block copolymer). The styrene / butadiene copolymer may be prepared by any known method including random polymerization, but is preferably prepared by continuous anionic polymerization or a coupling reaction. Of these, brominated triblock copolymers such as brominated styrene / butadiene / styrene block copolymers are particularly preferred.

  Other flame retardants include low molecular weight compounds such as polyglycerin dibromopropyl ether, tetrabromobisphenol A, tetrabromobisphenol-A-bis (2,3-dibromo-2-methylpropyl ether) and the like. Even if a flame retardant is used, the effect of lowering the amount of residual styrene in the expandable polystyrene resin particles of the final product can be obtained, but the molecular weight is lowered due to a decrease in the polymerization efficiency of the styrene monomer.

  The addition amount of the flame retardant in the present invention is 0.5 to 5 parts by weight, more preferably 0.7 to 3 parts by weight, with respect to 100 parts by weight of the styrene monomer. If the amount is less than 0.5 parts by weight, sufficient flame retardancy cannot be obtained. On the other hand, when the amount exceeds 5.0 parts by weight, the resulting foamable polystyrene resin particles may be deteriorated in molding processability and physical properties of the molded article, which is not preferable, and stability during styrene polymerization is impaired.

  Examples of the blowing agent used in the present invention include aliphatic hydrocarbons such as propane, isobutane, normal butane, isopentane, normal pentane, neopentane and other hydrocarbons having 3 to 5 carbon atoms, and ozone such as difluoroethane and tetrafluoroethane. Examples thereof include volatile blowing agents such as fluorinated hydrocarbons having a destruction coefficient of zero. Moreover, these foaming agents can also be used together. The amount used is preferably 3 parts by weight or more and 12 parts by weight or less, more preferably 5 parts by weight or more and 9 parts by weight or less, with respect to 100 parts by weight of the styrene resin particles.

  As the additive used in the present invention, a plasticizer, a bubble regulator, a flame retardant aid and the like can be used depending on the purpose. Examples of the plasticizer include stearic acid triglyceride, palmitic acid triglyceride, lauric acid triglyceride, stearic acid diglyceride, stearic acid monoglyceride and other fatty acid glycerides, palm oil, palm oil, palm kernel oil and other vegetable oils, dioctyl adipate, dibutyl sebacate And the like, and aliphatic hydrocarbons such as liquid paraffin, and organic hydrocarbons such as cyclohexane. These may be used in combination. Examples of the air conditioner include aliphatic bisamides such as methylene bis stearic acid amide and ethylene bis stearic acid amide, polyethylene wax, and the like. Examples of the flame retardant aid include high-temperature decomposition type organic substances such as cumene peroxide, dicumyl peroxide, t-butyl hydroperoxide, and 2,3-dimethyl-2,3-diphenylbutane.

  The expandable polystyrene resin particles of the present invention can be produced, for example, as follows. In a predetermined amount of aqueous suspension medium, in addition to the general polymerization initiator used for the polymerization of polystyrene, together with the compound represented by the general formula (1), a styrene monomer, brominated butadiene / vinyl aromatic copolymer Polymerization and other additives are added, and polymerization is performed at a predetermined temperature, preferably 90 ° C. or more and less than 100 ° C. for a certain period of time, and the polymerization process is performed when the conversion of the styrene monomer reaches 80% or more and 95% or less. Complete. After the polymerization step, a foaming agent is added, and the foaming agent impregnation step is performed at a predetermined temperature, preferably 110 ° C. or higher and 120 ° C. or lower for a predetermined time. After cooling, foamable styrene resin particles are obtained.

  When the temperature of the blowing agent impregnation step is 110 ° C. or more and 120 ° C. or less, in particular, since a compound having a 10-hour half-life temperature of the general formula (1) of 96 ° C. or more and 110 ° C. or less is used efficiently, Polymerization proceeds in a stable manner. However, when the temperature is less than 110 ° C., radical generation of the compound of the general formula (1) is reduced, and the productivity is lowered. When the temperature exceeds 120 ° C., the internal pressure of the polymerization machine is increased, and the polymerization machine having the pressure resistance of heavy equipment. Is required.

  When the polymerization conversion rate is less than 80%, after adding the foaming agent, the polymerization system becomes unstable in the foaming agent impregnation step of 110 ° C. or more and 120 or less, the cell structure of the foamed particles of the final product changes, and the foaming property When the polymerization conversion rate exceeds 95%, the polymerization time becomes longer and the productivity is lowered.

  The expandable polystyrene resin particles of the present invention obtained as described above have a residual styrene monomer amount of 300 ppm or less, preferably 250 pm or less. The lower limit is practically less than 0 ppm, so it is 1 ppm or more if dare to display.

  The expandable polystyrene resin particles of the present invention can be foamed by a known method to obtain a polystyrene resin foam molded article. For example, a method of once preparing pre-expanded particles and then filling the mold with the pre-expanded particles and then molding, or a method of directly filling the mold with expandable polystyrene resin particles and foam-molding can be used. The following method is mentioned as an example of the manufacturing method of a foaming molding. By heating the expandable styrene resin particles of the present invention at a temperature of about 80 to 110 ° C. using water vapor with a rotary stirring type prefoaming device, a prefoamed particle having a bulk ratio of about 30 to 100 ml / g is obtained and obtained. The obtained pre-expanded particles are filled in a mold having a desired shape, and heated at about 130 to 145 ° C. with water vapor or the like, whereby a polystyrene-based resin foam molded article can be obtained. The thus obtained polystyrene resin foam molded article of the present invention has flame retardancy and a small amount of residual styrene monomer.

  Polystyrene-based resin foam moldings are widely used as containers for storing fresh food, heat insulating materials for construction and civil engineering, and buffer materials for automobiles.

  Examples and Comparative Examples are given below, but the present invention is not limited thereby. In addition, about the molecular weight of resin in an Example and a comparative example, the amount of residual styrene in resin, the amount of phenyl acetylene in a styrene monomer, and evaluation of a flame retardance, it measured with the following method. “Parts” and “%” are based on weight unless otherwise specified.

(Molecular weight measurement method)
Expandable styrene resin particles were dissolved in tetrahydrofuran and measured by GPC (HLC-8020 manufactured by Tosoh Corporation, column: TSKgel Super HZM-H, column temperature: 40 ° C., flow rate: 0.35 ml / 1 min.). .

(Residual styrene measurement method)
Expandable styrenic resin particles are dissolved in methylene chloride (internal standard cyclopentanol), and gas chromatography GC-2014 (capillary column: Rtx-1, manufactured by GL Sciences, Inc.), column temperature condition: 50 → 80 ° C. After (3 ° C./min), the amount of residual styrene (ppm) contained in the expandable styrene resin particles was quantified using 80 → 180 ° C. temperature rise (10 ° C./min), carrier gas: helium.

(Measurement method of phenylacetylene in styrene monomer)
A calibration curve for the amount of phenylacetylene derived from the ratio of the amount of phenylacetylene and the amount of cyclopentanol was prepared using styrene having an amount of phenylacetylene of 0 ppm.

  The internal standard cyclopentanol is dissolved in styrene, and gas chromatography GC-2014 manufactured by Shimadzu Corporation (capillary column: Rtx-1 manufactured by GL Sciences, column temperature condition: 50 → 70 ° C. (3 ° C./min) After heating and holding at 70 ° C. for 30 minutes, the temperature was raised from 70 to 170 ° C. (10 ° C./min), and the amount of phenylacetylene (ppm) in styrene was quantified using a carrier gas: helium.

(Evaluation of flame retardancy)
The expandable polystyrene resin particles are heated with water vapor in a pressure type prefoaming machine (manufactured by Daikai Kogyo Co., Ltd.) to obtain prefoamed granules having a bulk magnification of 55 ml / g. Next, after this pre-foamed grain was cured at room temperature for 1 day, a flat foam was formed with a KR-57 molding machine manufactured by Daisen Industries. Evaluation of the flammability of the obtained polystyrene-based resin foam molded article was performed according to measurement method A described in JIS A 9511 (5.13 flammability), and the flame extinction time was within 3 seconds and there was no residue and the combustion limit indicator line. The case where it did not burn beyond this was passed, and the case other than that was made unacceptable.

Example 1
The amount of phenylacetylene in styrene was measured, and the amount of phenylacetylene was adjusted to 100 ppm.

  In a 6L autoclave with a stirrer, 96 parts by weight of water, 0.14 part by weight of tribasic calcium phosphate, 0.003 part by weight of sodium α-olein sulfonate, brominated butadiene / styrene copolymer ("EMERALD 3000" manufactured by Chemtura Co., Ltd.) containing bromine 64%) 1 part, benzoyl peroxide 0.1 part, t-butylperoxy-2-ethylhexyl monocarbonate (10 hour half-life temperature 99 ° C.) 0.25 part, dicumyl peroxide 0 as flame retardant aid .2 parts, 1.0 part of coconut oil was added as an additive, and then 100 parts by weight of styrene with the phenylacetylene amount adjusted to 100 ppm was added, the temperature was raised, and polymerization was carried out at 98 ° C. for 5 hours. 8 parts of normal rich butane (normal / iso = 70/30) was charged, and the temperature was raised to 117 ° C., followed by 4 hour foaming agent impregnation polymerization. Then, it cooled to 40 degreeC, taken out the expandable styrene-type resin particle, and dried.

  When the molecular weight of the obtained expandable styrene resin particles was measured by GPC, it was 285,000, and when the residual styrene content was measured by gas chromatography, it was 250 ppm. The flame retardancy was a flame extinguishing time of 2.5 seconds and passed without exceeding the combustion limit indicator line. The results are shown in Table 1.

(Example 2)
The same procedure as in Example 1 was carried out except that the amount of t-butylperoxy-2-ethylhexyl monocarbonate (10-hour half-life temperature 99 ° C.) was changed to 0.4 parts. The obtained results are shown in Table 1.

(Example 3)
Implemented except that t-butylperoxy-2-ethylhexyl monocarbonate (10-hour half-life temperature 99 ° C.) was changed to t-amyl peroxy-2-ethylhexyl monocarbonate (10-hour half-life temperature 98.5 ° C.) Performed as in Example 1. The obtained results are shown in Table 1.
(Example 4)
The same procedure as in Example 3 was repeated except that 0.4 part of t-amylperoxy-2-ethylhexyl monocarbonate (10 hour half-life temperature 98.5 ° C.) was changed. The obtained results are shown in Table 1.

(Example 5)
Example 1 except that t-butylperoxy-2-ethylhexyl monocarbonate (10-hour half-life temperature 99 ° C.) was changed to t-butyl peroxy-isopropyl monocarbonate (10-hour half-life temperature 95 ° C.) The same was done. The obtained results are shown in Table 1.

(Example 6)
The same procedure as in Example 1 was carried out except that the brominated butadiene / styrene copolymer (“EMERALD 3000” bromine content 64%, manufactured by Chemtura) was changed to 3 parts. The obtained results are shown in Table 1.

(Example 7)
The same procedure as in Example 1 was performed except that styrene having an amount of phenylacetylene adjusted to 200 ppm was used. The obtained results are shown in Table 1.

(Comparative Example 1)
t-Butylperoxy-2-ethylhexyl monocarbonate (10-hour half-life temperature 99 ° C.) was converted to 1,1-bis (t-amylperoxy) -3,3,5-trimethylcyclohexane (10-hour half-life temperature 92 The procedure was the same as in Example 1 except that the temperature was changed to [° C.]. The obtained results are shown in Table 1.

(Comparative Example 2)
t-Butylperoxy-2-ethylhexyl monocarbonate (10-hour half-life temperature 99 ° C.) was converted to 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane (10-hour half-life temperature 97 The procedure was the same as in Example 1 except that the temperature was changed to [° C.]. The obtained results are shown in Table 1.

(Comparative Example 3)
The same procedure as in Example 1 was performed except that the brominated butadiene / styrene copolymer ("EMERALD 3000" bromine content 64%, manufactured by Chemtura) was changed to 0.2 parts. The obtained results are shown in Table 1.

(Comparative Example 4)
Brominated butadiene / styrene copolymer ("EMERALD 3000" produced by Chemtura Inc., bromine content 64%) was converted to tetrabromobisphenol-A-bis (2,3-dibromo-2-methylpropyl ether) (Daiichi Kogyo Seiyaku Co., Ltd.) The product name was changed to the product name “Pyroguard SR130”). The obtained results are shown in Table 1.

(Comparative Example 5)
The same procedure as in Example 1 was performed except that styrene having a phenylacetylene content of 0 ppm was used. The obtained results are shown in Table 1.

(Comparative Example 6)
The same procedure as in Example 1 was performed except that the temperature in the foaming agent impregnation polymerization was 105 ° C. The obtained results are shown in Table 1.

(Comparative Example 7)
The same procedure as in Example 1 was performed except that the temperature in the foaming agent impregnation polymerization was 125 ° C. When the temperature was raised to 125 ° C. after adding the blowing agent, the internal pressure of the polymerization machine exceeded 1.8 MPa, and the operation was stopped.

Claims (7)

Compound 0 represented by the general formula (1) containing 0.5 to 5.0 parts by weight of a brominated polymer with respect to 100 parts by weight of a styrene monomer having a phenylacetylene content of 80 ppm or more .2 parts by weight or more and 0.6 parts by weight or less is used as a polymerization initiator to polymerize a styrene monomer, and propane, isobutane, normal butane, isopentane, normal pentane as a foaming agent during or after the polymerization And expandable polystyrene resin particles obtained by impregnating at least one selected from the group consisting of neopentane and having a residual styrene monomer content of 300 ppm or less particle.

(In the formula, R ₁ represents an alkyl group, and R ₂ represents a branched or straight chain alkyl group.)   2. The expandable polystyrene resin particles according to claim 1, wherein the brominated polymer is a brominated butadiene / vinyl aromatic copolymer. The expandable polystyrene resin particle according to claim 1 or 2, wherein the R ₁ structure of the general formula (1) is a methyl group or an ethyl group, and the R ₂ structure is a 2-ethylhexyl group or an isopropyl group. .   The expandable polystyrene resin particles according to any one of claims 1 to 3, wherein the compound represented by the general formula (1) has a 10-hour half-life temperature of 96 ° C to 110 ° C.   The expandable polystyrene resin particles according to any one of claims 1 to 4, wherein the foaming agent is impregnated at a temperature of 110 ° C to 120 ° C.   A polystyrene resin foam molded article obtained by foaming the expandable polystyrene resin particles according to any one of claims 1 to 5.   The manufacturing method of the expandable polystyrene-type resin particle in any one of Claims 1-5.